Ended explorer.exe process by accident, and fixed problem but now my computer doesnt boot properly.What do I do?

ended the process in the task manager a few days ago and instead of trying to run it again I turned my computer off.Then when it tried to start up it gave me a black screen with a blinking underscore and nothing else.I restored the computer to manufacturere settings but now everytime I try to restart my computer it goes back to that screen with the blinking underscore.So, I'm using my computer n on factory settings and I want to restore my computer to the state it was in before.P.S.Im using a Windows 7 HP Pavillion.When I restored the system I made a system back-up to an external hard drive and i would like to know how to restore those files as well.Thanks!

Solutions to the Problem Ended explorer.exe process by accident, and fixed problem but now my computer doesnt boot properly.What do I do?